In the prior art, an antenna device has been known. The antenna device includes a plurality of receiving antenna elements and performs predetermined signal processing such as a low frequency amplification process on received signals output from the receiving antenna elements (See Japanese Patent Application 2012-168156).
However, in the prior art, since each of the plurality of receiving antenna elements needs a circuit for performing the signal processing on the received signal, there is a problem in that the size of the entire antenna device is large.